Data communication networks may include various computers, servers, nodes, routers, switches, bridges, hubs, proxies, and other network devices coupled together and configured to pass data to one another. These devices will be referred to herein as “network elements.” Data is communicated through the data communication network by passing protocol data units, such as frames, packets, cells, or segments, between the network elements by utilizing one or more communication links. A particular protocol data unit may be handled by multiple network elements and cross multiple communication links as it travels between its source and its destination over the network.
Ethernet is a well known networking protocol that has been defined by the Institute of Electrical and Electronics Engineers (IEEE) as standard 802.1. Conventionally, Ethernet has been used to implement networks in enterprises such as businesses and campuses, and other technologies have been used to transport network traffic over longer distances. As the Ethernet standards have evolved over time, Ethernet has become more viable as a long distance transport technology as well.
Several fields that have been added to the Ethernet standards. The original Ethernet frame format specified by IEEE 802.1 includes a source address (C-SA) and a destination address (C-DA). IEEE 802.1Q added a Customer VLAN tag (C-Tag) which includes an Ethertype, TCI information, and customer VLAN ID. IEEE 802.1ad added a provider VLAN tag (S-Tag), which also includes an Ethertype, TCI information, and subscriber VLAN ID. The C-Tag allows the customer to specify a VLAN, while the S-Tag allows the service provider to specify a VLAN on the service provider's network for the frame. These tags also allow the customer and subscriber to specify other aspects which are not relevant to an understanding of the contribution disclosed herein. When a network is implemented using 802.1ad it may be referred to as Q in Q encapsulation or Provider Bridging (PB). A domain implemented using this Ethernet standard will be referred to as a Provider Bridging (PB) domain.
The Ethernet standard has evolved to also allow for a second encapsulation process to take place as specified in IEEE 802.1ah. Specifically, an ingress network element to a service provider's network may encapsulate the original Ethernet frame with an outer MAC header including a destination address on the service provider's network (B-DA), a source address on the service provider's network (B-SA), a VLAN ID (B-VID) and a service instance tag (I-SID). The combination of customer MAC addresses C-SA and C-DA with the I-SID are commonly referred to as the I-Tag. A domain implemented using this Ethernet standard will be referred to as a Provider Backbone Bridging (PBB) domain.
When a network is divided or where different networks owned by different entities, it is often desirable to connect the networks to allow data to be exchanged between the networks. However, the interconnection should occur such that control information is able to be contained within the network domain to limit visibility between domains. This allows customers to transmit data across the interconnected networks while maintaining the independence of the various network domains. However, conventional switching devices and methods do not allow for non-standard/pre-standard equipments to send frames with non-standard Ethertypes that ingress a network and still enable egress to be standard. Therefore, building networks with standard equipments in the core from other vendors has been difficult. Further, due to existing switching device and method configuration, conventional C-VLAN based networks have not been transparent across 802.1ad and 802.1ah clouds.
Due to the large number of protocols that may be used in the network domains, and the several different ways in which the network domains may be interconnected, it would be advantageous to provide a way in which the interconnection could be managed in a systemic and intelligent fashion.